Initialize Date parse cache with SMI instead of double to workaround sharing mutable heap numbers i…

src/date.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 114 matching lines @@
   if (!$isFinite(time)) return NAN;
   if ($abs(time) > MAX_TIME_MS) return NAN;
   return TO_INTEGER(time);
 }
 
 
 // The Date cache is used to limit the cost of parsing the same Date
 // strings over and over again.
 var Date_cache = {
   // Cached time value.
-  time: NAN,
+  time: 0,
   // String input for which the cached time is valid.
   string: null
 };
 
 
 function DateConstructor(year, month, date, hours, minutes, seconds, ms) {
   if (!%_IsConstructCall()) {
     // ECMA 262 - 15.9.2
     return (new $Date()).toString();
   }
@@ skipping 673 matching lines @@
     "toGMTString", DateToGMTString,
     "toUTCString", DateToUTCString,
     "getYear", DateGetYear,
     "setYear", DateSetYear,
     "toISOString", DateToISOString,
     "toJSON", DateToJSON
   ));
 }
 
 SetUpDate();